Friday afternoon: how not to wire a drill press

[Whales]

Very, very subtle.



This is the bottom end of the AC induction motor from my drill press.  Taken off from the area shown is a centrifugal switch that depresses the metal ring in the centre when the drill is not up to speed, presumably to limit inrush current.

[SteveH]

Whats subtle about it? The centrifugal switch takes the start windings out of circuit when the rotor is up to speed.

[ConKbot]

Subtle is the one lug resting against the frame, so either GFI trips, or the circuit breaker trip when you plug it in.  One will be a tad more exciting than the other.

[SeanB]

Or morre common is the frame is not grounded........

[Whales]

Subtle is the one lug resting against the frame, so either GFI trips, or the circuit breaker trip when you plug it in.  One will be a tad more exciting than the other.

Got it   My earth detection and resettable fuse both tripped, but not fast enough to avoid a lightshow.  The spade connector has a tiny, clean nick out of the side of it now, but is otherwise OK and the drill sustained no other damage.

I made sure the body was earthed and the wiring was otherwise the right way around.  It's interesting to note that it's grounded in two places: on the motor and at the switch on the main body.

[Paul Moir]

I thought it was a ground and the little bit of metal on it was a contact going to the shaft so you wouldn't have to go through the bearings.  Hey it even has a little green dot...
Pretty bad!  Is the crimp on the other fork as bad as it looks?

[Whales]

I thought it was a ground and the little bit of metal on it was a contact going to the shaft so you wouldn't have to go through the bearings.  Hey it even has a little green dot...

That green dot was a polarisation marking from when I pulled it apart, not knowing whether or not it was needed.  I might stick to black permanent markers from now on.

Pretty bad!  Is the crimp on the other fork as bad as it looks?

I'm assuming you're commenting on the very tight bend of the copper just as it leaves the crimp (I'm no crimping expert )  Yes they're both like that, but this part of the motor is stationary so it should not be too bad. 

I've just had to regut the motor again twice.  The first time because I scraped too much dirty grease out of the bearings without replacing it and the second because I had 'parts left over'.  It's all working well now.